This article presents a comparative analysis of the profile of youths from residential care and their peers in the juvenile justice system. We analysed all files in juvenile detention centres in Catalonia. There were 255 subjects in juvenile detention centres, of which 247 were male and only 8 female. Of this group, 34.5% are youths from residential care centres, and the remaining 65.5% are non-protected youths. Descriptive tests, t-tests, analysis of variance and chi-square tests were used for the analysis. The results corroborate with previous studies and reveal that there is a high population of youths in care in juvenile detention centres, and that more than half of them are of immigrant origin. Youths from residential care present differences when compared with youths who are not in care in terms of background, delinquency profile and the consumption of toxic substances. Immigrant youths from residential care mainly come from North Africa. On the contrary, the biggest immigrant group among youths who are not in care is from Latin America. Youths from residential care begin to commit offences (on average) a year later and commit more offences, mostly without interpersonal confrontation from their peers. Specifically, they commit more robberies with and without violence, but commit crimes against authorities and fewer murders. There are some differences in the consumption of toxic substances between both groups. Youths from residential care consume less hashish and alcohol.